Mechanical property and ballistic resistance of graphene platelets/B4C Ceramic armor prepared by spark plasma sintering

Boron carbide (B4C) ceramic toughened by graphene platelets (GPLs) was prepared by spark plasma sintering. Nonmetallic sintering aids Al2O3/Y2O3 were used to improve the sintering ability of boron carbide. Impacts of Al2O3/Y2O3 on mechanical properties and microstructure, and toughening mechanisms of graphene platelets were studied. When the content of Al2O3/Y2O3 is 5 wt%, the B4C ceramic was fully densified, and its Vickers harness and fracture toughness are 30.87 +/- 0.26 GPa and 5.76 +/- 0.37 MPa m(1/2), respectively. Fracture toughness of B4C ceramic containing 1.5 wt% GPLs is increased by 23.1% in comparison with that of B4C ceramic without GPLs, which is mainly attributed to the pining effect and packing capacity of GPLs. Ballistic resistance of the GPLs/B4C ceramic armor was experimentally studied with the method of depth of penetration test in contrast to two commercial ceramic armors (SiC, B4C). Compared to SiC and B4C, the penetration depth on the GPLs/B4C ceramic armor is the smallest, and the ballistic resistance of GPLs/B4C ceramic armor is increased by 50% and 12.5%, respectively.